System And Method For Improved Quality  Management In A Product Logistic Chain

ABSTRACT

A quality management system for products including a multiplicity of product unit specific indicators, each operative to provide a machine-readable indication of exceedence of at least one threshold by at least one product quality determining parameter, an indicator reader operative to read the product unit specific indicators and to provide output indications and a product type specific indication interpreter operative to receive the output indications and to provide human sensible, product unit specific, product quality status outputs.

REFERENCE TO RELATED APPLICATIONS

Reference is made to U.S. Provisional Patent Application Ser. No.60/746,646, filed May 7, 2006 and entitled “Efficiency and Quality in aLogistic Chain System and Manufacturing Processes,” and to U.S.Provisional Patent Application Ser. No. 60/804,072, filed Jun. 6, 2006and entitled “Presenting Barcoded Information on Time TemperatureIndicators,” the disclosures of which are hereby incorporated byreference and priority of which are hereby claimed pursuant to 37 CFR1.78(a) (4) and (5)(i).

FIELD OF THE INVENTION

The present invention relates to quality management systems andmethodologies and to indicators useful in such systems andmethodologies.

BACKGROUND OF THE INVENTION

The following U.S. Patents relate generally to the subject matter of thepresent application: U.S. Pat Nos. 6,758,397; 6,009,400 and RE 39,226.

SUMMARY OF THE INVENTION

The present invention seeks to provide improved quality managementsystems and methodologies as well as indicators useful in such systemsand methodologies.

There is thus provided in accordance with a preferred embodiment of thepresent invention a quality management system for products including amultiplicity of product unit specific indicators, each operative toprovide a machine-readable indication of exceedence of at least onethreshold by at least one product quality determining parameter, anindicator reader operative to read the product unit specific indicatorsand to provide output indications and a product type specific indicationinterpreter operative to receive the output indications and to providehuman sensible, product unit specific, product quality status outputs.

Preferably, the indicator reader is a bar code reader. Additionally oralternatively, the machine-readable indications are in the form of barcodes. Additionally, the bar codes are one-dimensional bar codes.Alternatively, the bar codes are two-dimensional bar codes.

Preferably, the at least one threshold includes at least a temperaturethreshold and an elapsed time threshold. Additionally or alternatively,the at least one threshold includes at least a pH threshold.

Preferably, the machine-readable indications each include a variable barcode having a first readable state including digital indicia and atleast start and stop code indicia and at least a second readable statewherein at least one of the start and stop code indicia which appear inthe first readable state form part of the digital indicia in the secondreadable state.

Preferably, the multiplicity of product unit specific indicators areeach operative to provide machine-readable indications of exceedence ofat least two thresholds by at least one product quality determiningparameter.

In another preferred embodiment the machine-readable indications eachinclude a variable bar code having at least three readable statesincluding a first readable state including digital indicia and at leaststart and stop code indicia, and at least a second readable statewherein at least one of the start and stop code indicia which appear inthe first readable state form part of the digital indicia in the secondreadable state.

There is also provided in accordance with another preferred embodimentof the present invention a product unit specific indicator operative toprovide a machine-readable indication of exceedence of at least onethreshold by at least one product quality determining parameter, theindicator including a variable bar code having a first readable stateincluding digital indicia and at least start and stop code indicia andat least a second readable state wherein at least one of the start andstop code indicia which appear in the first readable state form part ofthe digital indicia in the second readable state.

There is further provided in accordance with yet another preferredembodiment of the present invention a product unit specific indicatoroperative to provide a machine-readable indication of exceedence of atleast one threshold by at least one product quality determiningparameter, the indicator including a variable bar code having a fixedbar code portion and at least one selectably appearing bar code portion,both the fixed bar code portion and the at least one selectablyappearing bar code portion being readable by a bar code reader.

There is even further provided in accordance with still anotherpreferred embodiment of the present invention a product unit specificindicator operative to provide a machine-readable indication ofexceedence of at least one threshold by at least one product qualitydetermining parameter, the indicator including a variable bar codehaving a fixed bar code portion representing a first number of digitsand at least one selectably appearing bar code portion which appearsalongside the fixed bar code portion, the at least one selectablyappearing bar code portion representing at least one additional digit.

Preferably, the at least one selectably appearing bar code portionappears alongside the fixed bar code portion in response to exceedenceof the at least one threshold. Alternatively, the at least oneselectably appearing bar code portion disappears in response toexceedence of the at least one threshold.

There is also provided in accordance with another preferred embodimentof the present invention an event indicator operative to provide amachine-readable indication of occurrence of at least one event, theindicator including a variable bar code having a first readable stateincluding digital indicia and at least start and stop code indicia andat least a second readable state wherein at least one of the start andstop code indicia which appear in the first readable state form part ofthe digital indicia in the second readable state.

There is still further provided in accordance with yet another preferredembodiment of the present invention an event indicator operative toprovide a machine-readable indication of occurrence of at least oneevent, the indicator including a variable bar code having a fixed barcode portion and at least one selectably appearing bar code portion,both the fixed bar code portion and the at least one selectablyappearing bar code portion being readable by a bar code reader.

There is even further provided in accordance with still anotherpreferred embodiment of the present invention an event indicatoroperative to provide a machine-readable indication of occurrence of atleast one event, the indicator including a variable bar code having afixed bar code portion representing a first number of digits and atleast one selectably appearing bar code portion which appears alongsidethe fixed bar code portion, the at least one selectably appearing barcode portion representing at least one additional digit.

There is also provided in accordance with yet another preferredembodiment of the present invention a method for quality management forproducts including employing a multiplicity of product unit specificindicators each to provide a machine-readable indication of exceedenceof at least one threshold by at least one product quality determiningparameter; reading the product unit specific indicators and providingoutput indications therefrom and interpreting the output indications toprovide human sensible, product unit specific, product quality statusoutputs.

There is further provided in accordance with even a further preferredembodiment of the present invention a method for providing amachine-readable indication of exceedence of at least one threshold byat least one product quality determining parameter including employingan indicator which provides a variable bar code having a first readablestate including digital indicia and at least start and stop code indiciaand at least a second readable state wherein at least one of the startand stop code indicia which appear in the first readable state form partof the digital indicia in the second readable state.

There is also provided in accordance with still another preferredembodiment of the present invention a method for providing amachine-readable indication of exceedence of at least one threshold byat least one product quality determining parameter including employingan indicator which provides a variable bar code having a fixed bar codeportion and at least one selectably appearing bar code portion andreading both the fixed bar code portion and the at least one selectablyappearing bar code portion using a bar code reader.

There is further provided in accordance with yet another preferredembodiment of the present invention a method for providing amachine-readable indication of exceedence of at least one threshold byat least one product quality determining parameter including employingan indicator which provides a variable bar code having a fixed bar codeportion representing a first number of digits and at least oneselectably appearing bar code portion which appears alongside the fixedbar code portion, the at least one selectably appearing bar code portionrepresenting at least one additional digit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIGS. 1A, 1B, 1C and 1D together are a simplified illustration of asystem and methodology for quality management constructed and operativein accordance with a preferred embodiment of the present invention;

FIG. 2A is a simplified illustration of a quality indicator constructedand operative in accordance with a preferred embodiment of the presentinvention for indicating temperature history;

FIG. 2B is a simplified illustration of a quality indicator constructedand operative in accordance with another preferred embodiment of thepresent invention for indicating elapsed time and temperature history;

FIG. 2C is a simplified illustration of a quality indicator constructedand operative in accordance with another preferred embodiment of thepresent invention for separately indicating elapsed time and temperaturehistory;

FIG. 2D is a simplified illustration of a quality indicator constructedand operative in accordance with yet another preferred embodiment of thepresent invention for indicating pH history;

FIG. 2E is a simplified illustration of a quality indicator constructedand operative in accordance with still another preferred embodiment ofthe present invention for indicating humidity history;

FIG. 2F is a simplified illustration of a quality indicator constructedand operative in accordance with a further preferred embodiment of thepresent invention for indicating impact history;

FIG. 2G is a simplified illustration of a quality indicator constructedand operative in accordance with a still further preferred embodiment ofthe present invention for indicating orientation history;

FIG. 3A is a simplified illustration of a quality indicator constructedand operative in accordance with a preferred embodiment of the presentinvention for indicating elapsed time and temperature history;

FIG. 3B is a simplified illustration of a quality indicator constructedand operative in accordance with another preferred embodiment of thepresent invention for indicating temperature and humidity history;

FIG. 3C is a simplified illustration of a quality indicator constructedand operative in accordance with another preferred embodiment of thepresent invention for indicating elapsed time, temperature and humidityhistory;

FIG. 4A is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2A, in accordance with a preferredembodiment of the present invention;

FIG. 4B is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2B, in accordance with a preferredembodiment of the present invention;

FIG. 4C is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2C, in accordance with a preferredembodiment of the present invention;

FIG. 4D is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2D, in accordance with a preferredembodiment of the present invention;

FIG. 4E is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2E, in accordance with a preferredembodiment of the present invention;

FIG. 4F is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2F, in accordance with a preferredembodiment of the present invention;

FIG. 4G is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 2G, in accordance with a preferredembodiment of the present invention;

FIG. 5A is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 3A in accordance with a preferredembodiment of the present invention;

FIG. 5B is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 3B in accordance with a preferredembodiment of the present invention;

FIG. 5C is a simplified illustration of the structure and operation ofan example of the indicator of FIG. 3C in accordance with a preferredembodiment of the present invention;

FIG. 6 is a simplified illustration of a method and apparatus forproducing indicators constructed and operative in accordance with thepresent invention;

FIG. 7A is a simplified illustration of the structure and operation of aquality management system constructed and operative in accordance with apreferred embodiment of the present invention in the context of asupermarket; and

FIG. 7B is a simplified illustration of the structure and operation of aquality management system constructed and operative in accordance with apreferred embodiment of the present invention in the context of asupermarket.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is now made to FIGS. 1A, 1B, 1C and 1D, which together are asimplified illustration of a system and methodology for qualitymanagement constructed and operative in accordance with a preferredembodiment of the present invention. As seen in FIGS. 1A-1D, there isshown a quality management system and methodology for products includinga multiplicity of product unit specific indicators, here shown in theform of changeable barcode indicators, each operative to provide amachine-readable indication of exceedence of at least one threshold byat least one product quality determining parameter, at least oneindicator reader operative to read the product unit specific indicatorsand to provide output indications and a product type specific indicationinterpreter operative to receive the output indications and to providehuman sensible, product unit specific, product quality status outputs.

The changeable barcode indicator may incorporate a product code such asa UPC code.

Preferably, the product unit specific indicator is operative to providea machine-readable indication of exceedence of at least one threshold byat least one product quality determining parameter and in a preferredembodiment provides a variable bar code having a first readable stateincluding digital indicia and at least start and stop code indicia andat least a second readable state wherein at least one of the start andstop code indicia which appear in the first readable state form part ofthe digital indicia in the second readable state.

Additionally or alternatively, the indicator provides a variable barcode having a fixed bar code portion and at least one selectablyappearing bar code portion, both the fixed bar code portion and the atleast one selectably appearing bar code portion being readable by aconventional bar code reader.

Additionally or alternatively, the indicator provides a variable barcode having a fixed bar code portion representing a first number ofdigits and at least one selectably appearing bar code portion whichappears alongside the fixed bar code portion, the at least oneselectably appearing bar code portion representing at least oneadditional digit.

Turning now to FIGS. 1-1D, the present invention is illustrated in thecontext of a typical application, here a meat processing plant. Aproduct unit specific indicator 100 is attached to or otherwiseincorporated into each package 102 of processed meat. A package bearinga product unit specific indicator 100 may be an individual packagesuitable for retail sale and/or a carton containing a plurality of suchindividual packages. In the illustrated embodiment, packages 102 includeboth alternatives.

It is also a possibility that different types of indicators 100 may beemployed for different types of packages. For example, the indicatorused on a carton containing a plurality of individual packages may bemore or less accurate or have a greater or lesser dynamic range ofindications than the indictor used on an individual package. Forexample, the indicator on a carton may include an indicator capable ofindicating exceedance of additional thresholds, not included on theindicators of individual packages contained therein, or fewer thresholdsthan the indicators of individual packages contained therein.

In accordance with a preferred embodiment of the present invention, theindicators 100 may be assembled and/or actuated at the same location orat a location adjacent that at which the indicators 100 are associatedwith packages 102. A suitable indicator assembler/actuator is indicatedby reference numeral 103.

In the illustrated embodiment, the indicator includes a 2 of 5interleaved bar code. The indicator is typically calibrated to remain ina first readable state as long as it remains at a temperature less thanor equal to 4 degrees Celsius and not more than a predetermined timeperiod, typically one week, has elapsed since manufacture or otheractuation of the indicator. This first readable state is indicated byreference numeral 104. It is seen that so long as the temperature of thepackage 102 does not exceed 4 degrees Celsius and one week has notelapsed since manufacture or other actuation of the indicator, theindicator 100 remains in the first readable state 104. At any stage,such as upon delivery to the customer, the indicator 100 can be readwith a conventional bar code reader 106, which preferably communicateswith a remote quality indication server 108 and provides an immediateindication of a quality parameter, such as an OK indication 110, to aninspector.

If and when the temperature of the package 102 exceeds 4 degreesCelsius, such as when it reaches 15 degrees Celsius, the indicatorassumes a second readable state, indicated by reference numeral 112.This second readable state does not change notwithstanding that thetemperature of the package 102 subsequently returns to an acceptabletemperature, such as 4 degrees Celsius. Accordingly, upon inspection, asupon delivery to the customer, upon reading the indicator 100 by aninspector using a conventional bar code reader 106, the bar code in itssecond readable state 112 preferably provides information to the qualityindication server 108 which enables the server to provide an immediateindication of a quality parameter, such as a BAD indication 114. ThisBAD indication 114 indicates that at some time in the history of theindicator 100, the package 102 to which it was attached was at atemperature exceeding 4 degrees Celsius and that this event has renderedthe specific product in package 102 unacceptable for sale.

It is appreciated that whereas machine reading of the indicator 100provides an indication of whether or not a given event has occurred, theindication of a quality parameter by quality indication server 108provides an indication of whether and to what extent that event hasaffected the quality of a given product with which the indicator 100 isassociated. It is appreciated that there may be a great variation in theeffect of a given event depending on the type of product. Thus, forexample, exposure to 15 degrees Celsius may cause fresh meat to berendered unfit for sale but may not appreciably affect the quality orsaleability of oranges.

Turning now specifically to FIGS. 1C and 1D, it is seen that indicator100 may additionally and independently serve to indicate elapsed time.Thus, upon exceedance of the predetermined time period followingmanufacture or other actuation of the indicator 100, the indicator 100assumes a third readable state 118 which indicates that a predeterminedamount of time has elapsed. Upon elapse of a further predeterminedamount of time, typically a second week, the indicator 100 may assume afourth readable state 120.

Accordingly, upon inspection, as indicated by reference numeral 122, asupon periodic stock inspection at a retail site, upon reading theindicator 100 by an inspector using a conventional bar code reader 106,the bar code in its third readable state 118 provides information to thequality indication server 108 which enables the server to provide animmediate indication of a quality parameter, such as a SELL SOONindication 124. This SELL SOON indication 124 indicates that, since thepredetermined time interval has elapsed, the package 102 to which it wasattached should be positioned and/or priced for immediate sale.

Turning now to FIG. 1D, it is seen that upon further inspection, asindicated by reference numeral 132, as upon periodic stock inspection atthe retail site, upon reading the indicator 100 by an inspector using aconventional bar code reader 106, the bar code in its fourth readablestate 120 provides information to the quality indication server 108which enables the server to provide an immediate indication of a qualityparameter, such as an EXPIRED indication 134. This EXPIRED indication134 indicates that the package 102 to which it was attached should bediscarded, since the further predetermined time period has elapsed.

Additionally or alternatively, the further inspection may take placeautomatically at the checkout, where the indicator 100 is read by acheckout scanner 136. In such a case, the bar code in its fourthreadable state 120 provides information to the quality indication server108 which enables the server to provide an immediate indication of aquality parameter, such as a DO NOT SELL indication 138, to the checkoutclerk. This DO NOT SELL indication 138 indicates that the package 102 towhich it was attached may not be sold since the further predeterminedtime period has elapsed. It is appreciated that the DO NOT SELLindication functionality described above provides a high level ofcontrol in implementing package-specific shelf-life restrictions andthus, by eliminating uncertainty regarding the shelf life of a givenproduct, may enable packaged products which have been maintained underoptimal conditions to have longer shelf lives than would otherwise bepossible.

Reference is now made to FIGS. 2A-2G, which are simplified illustrationsof event indicators constructed and operative in accordance with apreferred embodiment of the present invention, respectively, forindicating temperature history, elapsed time and temperature history, pHhistory, humidity history, impact history and orientation history.

FIG. 2A illustrates a package of meat 200 including a temperature eventindicator 202 constructed and operative in accordance with a preferredembodiment of the present invention. As illustrated in FIG. 2A,indicator 202 includes a bar code which is in a first readable state204, typically 0123, when the temperature of the package 200 is lessthan 5 degrees Celsius and is in a second readable state 206, typically012312, including an additional portion 208, when the temperature of thepackage 200 is more than 5 degrees Celsius, such as 15 degrees Celsius.In the illustrated embodiment once the second readable state 206 isreached, the indicator preferably does not thereafter revert to thefirst readable state 204 notwithstanding that the temperature of thepackage 200 subsequently returns to 4 degrees Celsius.

FIG. 2B illustrates a package of grapes 210 including a combinationelapsed time and temperature indicator 212 constructed and operative inaccordance with a preferred embodiment of the present invention. Asillustrated in FIG. 2B, indicator 212 includes a bar code which is in afirst readable state 214, typically 0123, when the temperature of thepackage 210 has not exceeded 4 degrees Celsius for a cumulative periodof more than 48 hours and is in a second readable state 216, typically012312, including an additional portion 218, when the temperature of thepackage 210 has been more than 4 degrees Celsius, such as 15 degreesCelsius, for at least a cumulative period of 48 hours. In theillustrated embodiment once the second readable state 216 is reached,the indicator does not revert to the first readable state 214notwithstanding that the temperature of the package 210 subsequentlyreturns to 4 degrees Celsius.

FIG. 2C illustrates a package of meat 220 including an indicator 221 forseparately indicating elapsed time and temperature, constructed andoperative in accordance with a preferred embodiment of the presentinvention. As illustrated in FIG. 2C, indicator 221 includes a bar codewhich is in a first readable state 222, typically 0123, when thetemperature of the package 220 has not exceeded a temperature threshold,typically 4 degrees Celsius, and no more than a first predetermined timeperiod, typically one week, has elapsed since packaging. The indicator221 shifts to a second readable state 223, typically 350123, including afirst additional portion 224, when the temperature of the package 220exceeds the temperature threshold, such as 15 degrees Celsius, and nomore than the first predetermined time period has elapsed sincepackaging. The indicator 221 shifts to a third readable state 225,typically 012312, including a second additional portion 226, when thefirst predetermined time period has elapsed since packaging but thetemperature of the package 220 has not exceeded the temperaturethreshold and shifts to a fourth readable state 227, typically 01231212,including second additional portion 226 and a third additional portion228, when a second predetermined time period, typically two weeks, haselapsed since packaging, if the temperature has not exceeded thetemperature threshold. If the temperature of package 220 has exceededthe temperature threshold and the first predetermined time period haselapsed since packaging, the indicator shifts to a fifth readable state229, typically 35012312, including first additional portion 224 andsecond additional portion 226.

FIG. 2D illustrates a container of milk 230 including a pH eventindicator 232 constructed and operative in accordance with a preferredembodiment of the present invention. As illustrated in FIG. 2D,indicator 232 includes a bar code which is in a first readable state234, typically 0123, when the pH of the milk is more than 5 and is in asecond readable state 236, typically 012312, including a firstadditional portion 237, when the pH of the milk is between 4 and 5. Whenthe pH of the milk reaches a lower level, such as 4 or below, theindicator 232 reaches a third readable state 238, typically 01231212,including first additional portion 237 and a second additional portion239.

FIG. 2E illustrates a container of cereal 240 including a humidity eventindicator 242 constructed and operative in accordance with a preferredembodiment of the present invention. As illustrated in FIG. 2E,indicator 242 includes a bar code which is in a first readable state244, typically 0123, when the relative humidity of the cereal does notexceed a predetermined humidity threshold, typically 15%, and is in asecond readable state 246, typically 012312, including an additionalportion 248, when the relative humidity of the cereal is greater thanthe predetermined humidity threshold, such as 60%.

FIG. 2F illustrates a packaged impact sensitive product 250, such as acomputer, including an impact event indicator 252 constructed andoperative in accordance with a preferred embodiment of the presentinvention. As illustrated in FIG. 2F, indicator 252 includes a bar codewhich is in a first readable state 254, typically 0123, when no impactexceeding an impact threshold, typically 10G, has occurred and is in asecond readable state 256, typically 012312, including an additionalportion 258, when an impact exceeding the impact threshold has occurred.

FIG. 2G illustrates a packaged orientation sensitive product 260, suchas a refrigerator, including an orientation event indicator 262constructed and operative in accordance with a preferred embodiment ofthe present invention. As illustrated in FIG. 2G, indicator 262 includesa bar code which is in a first readable state 264, typically 0123, whenthe product has not changed its angular orientation by more than 170degrees from its original upright orientation and is in a secondreadable state 266, typically 012312, including an additional portion268, when a change of orientation of more than 170 degrees has occurred,even if subsequently the product 260 has been returned to its originalupright orientation.

It is appreciated that the present invention also encompasses indicatorswherein the first readable state has more digits than the secondreadable state and similarly where each subsequent readable state hasfewer digits than the preceding readable state. This may readily beachieved in accordance with the present invention, for example, byinitially locating a black background behind transparent areas, similarto the transparent areas described hereinbelow with reference to FIGS.4A-5C, and then, as the result of a change in an environmentalparameter, changing that black background to white. Alternatively, thismay be achieved by employing white on black background bar codes insteadof black on white background bar codes as shown in the examples above.

Reference is now made to FIG. 3A, which is a simplified illustration ofa package of meat 300 including an indicator 302 for separatelyindicating elapsed time and temperature, constructed and operative inaccordance with a preferred embodiment of the present invention. Theindicator 302 of FIG. 3A is a two-dimensional indicator which includes aplurality of fixed cells 303 and a plurality of variable cells 304, eachof which is capable of providing a machine-readable indication of anevent. It is appreciated that at a basic level, the indicator 302 ofFIG. 3A provides similar information to the indicator 221 of FIG. 2C.However, due to the fact that indicator 302 contains a plurality ofvariable cells 304, it may readily be employed to indicate a pluralityof temperature levels or extents of elapsed time.

As seen in FIG. 3A, indicator 302 includes at least a first variablearea 305, typically including 3 variable cells 304, which is in a firstreadable state, such as a white state 306, when the temperature of thepackage 220 has not exceeded a temperature threshold, typically 4degrees Celsius. The at least first variable area 305 shifts to a secondreadable state, such as a black state 308, when the temperature of thepackage 300 exceeds the temperature threshold, such as 15 degreesCelsius. An at least second variable area 309, typically including 4variable cells 304, is in a first readable state, such as a white state310, prior to elapse of a first predetermined time period, such as oneweek, since packaging and shifts to a second readable state, such as ablack state 312, once the first predetermined time period has elapsedsince packaging.

An at least third variable area 313, typically including 2 variablecells 304, is in a first readable state, such as a white state 314,prior to elapse of a second predetermined time period, greater than thefirst predetermined time period, such as two weeks, since packaging andshifts to a second readable state, such as a black state 316, once thesecond predetermined time period has elapsed since packaging.

Thus, it may be appreciated that when package 300 is in the statedesignated by the letter A, the first, second and third variable areas305, 309 and 313 are all in their first readable state, indicating thatthe temperature of the package has not exceeded the temperaturethreshold and the elapsed time since packaging has not exceeded thefirst predetermined time period.

When package 300 is in the state designated by the letter B, second andthird variable areas 309 and 313 are both in their first readable state,while the first variable area 305 is in its second readable stateindicating that the temperature of the package has exceeded thetemperature threshold and the elapsed time since packaging has notexceeded the first predetermined time period.

When package 300 is in the state designated by the letter C, the firstand third variable areas 305 and 313 are in their first readable state,while the second variable area 309 is in its second readable state,indicating that the temperature of the package has not exceeded thetemperature threshold and the elapsed time since packaging has exceededthe first predetermined time period but not the second predeterminedtime period.

When package 300 is in the state designated by the letter D, the first,second and third variable areas 305, 309 and 313 are all in their secondreadable state, indicating that the temperature of the package hasexceeded the temperature threshold and the elapsed time since packaginghas exceeded the first and second predetermined time periods.

When package 300 is in the state designated by the letter E, the firstvariable area 305 is in its first readable state, while the second andthird variable areas 309 and 313 are in their second readable state,indicating that the temperature of the package has not exceeded thetemperature threshold and the elapsed time since packaging has exceededthe first and second predetermined time periods.

Reference is now made to FIG. 3B, which is a simplified illustration ofa package of cereal 320 including an indicator 322 for separatelyindicating humidity and temperature, constructed and operative inaccordance with a preferred embodiment of the present invention. Theindicator 322 of FIG. 3B is a two-dimensional indicator which includes aplurality of fixed cells 323 and a plurality of variable cells 324, eachof which is capable of providing a machine-readable indication of anevent. Due to the fact that indicator 322 contains a plurality ofvariable cells 324, it may readily be employed to indicate a pluralityof temperature levels and humidity levels.

As seen in FIG. 3B, indicator 322 includes at least a first variablearea 325, typically including 4 variable cells 324, which is in a firstreadable state, such as a white state 326, when the humidity of thepackage 320 is less than a humidity threshold, such as 30%. The at leastfirst variable area 325 shifts to a second readable state, such as ablack state 328, when the humidity of package 320 exceeds the humiditythreshold, such as 60%. It is appreciated that depending on theconstruction of the indicator, the humidity that is indicated by firstvariable area 325 is either the ambient relative humidity oralternatively the humidity of the contents of the package.

An at least second variable area 329, typically including 2 variablecells 324, is in a first readable state, such as a white state 330, whenthe temperature of the package 320 has not exceeded a temperaturethreshold, such as 25 degrees Celsius, and shifts to a second readablestate, such as a black state 332, if temperature of the package 320exceeds the temperature threshold, such as 33 degrees Celsius. An atleast third variable area 333, typically including 3 variable cells 324,is also in a first readable state, such as a white state 334, when thetemperature of the package 320 has not exceeded the temperaturethreshold, and also shifts to a second readable state, such as a blackstate 336, when the temperature of the package 320 exceeds thetemperature threshold.

Thus, it may be appreciated that when package 320 is in the statedesignated by the letter A, the first, second and third variable areas325, 329 and 333 are all in their first readable state, indicating thatthe temperature of the package has not exceeded the temperaturethreshold and the humidity has not exceeded the humidity threshold.

When package 300 is in the state designated by the letter B, first,second and third variable areas 325, 329 and 333 are all in their secondreadable state, indicating that the temperature of the package hasexceeded the temperature threshold and the humidity has exceeded thehumidity threshold.

It is appreciated that in the illustrated embodiment of FIG. 3B variableareas 329 and 333 provide identical temperature information. It isappreciated that multiple variable areas may alternatively be used toindicate multiple temperature levels, similar to the indicatorillustrated in FIG. 3C.

Reference is now made to FIG. 3C, which is a simplified illustration ofa package of cheese 350 including an indicator 352 for separatelyindicating elapsed time, humidity and temperature, constructed andoperative in accordance with a preferred embodiment of the presentinvention. The indicator 352 of FIG. 3C is a two-dimensional indicatorwhich includes a plurality of fixed cells 353 and a plurality ofvariable cells 354, each of which is capable of providing amachine-readable indication of an event. Due to the fact that indicator352 contains a plurality of variable cells 354, it may readily beemployed to indicate a plurality of temperature levels, extents ofelapsed time and humidity levels.

As seen in FIG. 3C, indicator 352 includes at least a first variablearea 355, typically including 3 variable cells 354, which is in a firstreadable state, such as a white state 356, prior to elapse of a firsttime period, typically one week, since packaging and shifts to a secondstate, such as a black state 358, once the first time period has elapsedsince packaging. An at least second variable area 359, typicallyincluding 4 variable cells 354, is in a first state, such as a whitestate 360, prior to elapse of a second time period, greater than thefirst time period, typically two weeks, since packaging and shifts to asecond state, such as a black state 362, once the second time period haselapsed since packaging.

An at least third variable area 363, typically including 2 variablecells 354, is in a first readable state, such as white state 364, whenthe humidity is less than a first humidity threshold, typically 10%, andshifts to a second state, such as a black state 366, if the humidityexceeds the first humidity threshold, such as 30%. An at least fourthvariable area 367, typically including 2 variable cells 354, is in afirst state, such as a white state 368, when the humidity is less than asecond humidity threshold, greater than the first humidity threshold,typically 40%, and shifts to a second state, such as a black state 370,if the humidity exceeds the second humidity threshold, such as 60%.

An at least fifth variable area 371, typically including 3 variablecells 354, is in a first state, such as white state 372, when thetemperature of the package 350 has not exceeded a first temperaturethreshold, typically 5 degrees Celsius. The at least first variable area355 shifts to a second readable state, such as a black state 374, whenthe temperature of the package 350 exceeds the first temperaturethreshold, such as 12 degrees Celsius. An at least sixth variable area385, typically including 3 variable cells 354, is in a first readablestate, such as white state 386, when the temperature of the package 350has not exceeded a second temperature threshold, greater than the firsttemperature threshold, typically 12 degrees Celsius. The at least secondvariable area 385 shifts to a second readable state, such as a blackstate 388, when the temperature of the package 350 exceeds the secondtemperature threshold, such as 20 degrees Celsius.

It is appreciated that depending on the construction of the indicator,the humidity that is indicated by variable areas 363 and 367 is theambient relative humidity or alternatively the humidity of the contentsof the package.

Thus it may be appreciated that when package 350 is in the statedesignated by the letter A, the first to sixth variable areas 355, 359,363, 367, 371 and 385 are all in their first readable state, indicatingthat less than the first time period has elapsed since packaging, thehumidity has not exceeded the first humidity threshold and thetemperature of the package has not exceeded the first temperaturethreshold.

When package 350 is in the state designated by the letter B, first,third and fifth variable areas 355, 363 and 371 are all in their secondstate, and second, fourth and sixth variable areas 359, 367 and 385 areall in their first state, indicating that the time duration frompackaging has exceeded the first time period but has not exceeded thesecond time period, the humidity has exceeded the first humiditythreshold but has not exceeded the second humidity threshold and thetemperature of the package has exceeded the first temperature thresholdbut has not exceeded the second temperature threshold.

When package 350 is in the state designated by the letter C, the firstto sixth variable areas 355, 359, 363, 367, 371 and 385 are all in theirsecond state, indicating that the time duration from packaging hasexceeded the first and second time periods, the humidity has exceededthe first and second humidity thresholds and the temperature of thepackage has exceeded the first and second temperature thresholds.

It is appreciated that while the illustrated embodiments of FIGS. 3A-3Cinclude variable areas including multiple variable cells, each of thevariable areas may include a single variable cell or multiple variablecells. Typically, variable areas include multiple variable cells toenhance readability of the variable areas.

Reference is now made to FIG. 4A, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 202 ofFIG. 2A for indicating temperature history. As seen in FIG. 4A, theindicator, here designated by reference numeral 400, preferably includesa bar code defining layer 402, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 404 andalongside it a plurality of transparent areas 406, which, if colored andread together with the bar code in the first readable state 404, providea bar code in a second readable state 408. It is appreciated that theremainder of the bar code defining layer 402, other than the bar code ina first readable state 404 and the transparent areas 406, is preferablyprinted in a white color or a color defining high contrast with respectto the bar code in the first readable state 404.

Disposed behind transparent areas 406 there is preferably provided atemperature responsive coloring element 410, such as a piece of paperimpregnated with a coloring agent, such as Nigrosine, Alcohol soluble, ablack color dye [CAS: 11099-03-9], commercially available from AcrosOrganics of Geel, Belgium, dissolved in 2′-Hydroxyacetophenone 99.9%solvent [CAS: 118-93-4], commercially available from Acros Organics ofGeel, Belgium. Disposed intermediate temperature responsive colorelement 410 and bar code defining layer 402 is an opaque layer 412 of acolor which defines high contrast with respect to the bar code in afirst readable state 404.

When the indicator 400 is maintained at 4 degrees Celsius, the indicatoris in the state designated by A in FIG. 4A.

When the temperature at the indicator rises above 4 degrees Celsius, thecoloring agent on coloring element 410 begins to melt and be releasedfrom coloring element 410 and begins to diffuse through the opaque layer412, as designated by B in FIG. 4A. Thus, when the temperature exceeds 4degrees Celsius for at least a minimum time, such as one minute, thecoloring agent rapidly diffuses through opaque layer 412, such that theportions of the opaque layer 412 which are readable through thetransparent areas 406 appear similarly to the bar code in the firstreadable state 404 and can be read together therewith as a single barcode as in the state designated by C in FIG. 4A.

Reference is now made to FIG. 4B, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 212 ofFIG. 2B for indicating temperature/time history. As seen in FIG. 4B, theindicator, here designated by reference numeral 420, preferably includesa bar code defining layer 422, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 424 andalongside it a plurality of transparent areas 426, which, if colored andread together with the bar code in the first readable state 424, providea bar code in a second readable state 428. It is appreciated that theremainder of the bar code defining layer 422, other than the bar code ina first readable state 424 and the transparent areas 426, is preferablyprinted in a white color or a color defining high contrast with respectto the bar code in the first readable state 424.

Disposed behind bar code defining layer 422 is a temperature/timeresponsive coloring assembly 430, including a temperature responsiverelease coloring element 432, a relatively long-term coloring agentdiffusion pathway defining element 434 and a relatively quick coloringagent diffusion region defining element 436. The temperature responsiverelease coloring element 432 preferably comprises a substrate, such aspaper or a non-woven fabric impregnated with a coloring agent, such asNigrosine, Alcohol soluble, a black color dye [CAS: 11099-03-9](commercially available from Acros Organics of Geel, Belgium, dissolvedin 2′-Hydroxyacetophenone 99.9% solvent [CAS: 118-93-4], commerciallyavailable from Acros Organics of Geel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 434 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 432 and an oppositeend of which extends to element 436. Relatively quick coloring agentdiffusion region defining element 436 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 434, thus ensuring that a timewhen the bar code is between its first and second readable states isminimized. It is appreciated that alternatively element 436 may beobviated and element 434 extends under all of transparent areas 426.

When the indicator 420 is maintained at 4 degrees Celsius, the indicatoris in the state shown designated by A in FIG. 4B.

When the temperature at the indicator rises above 4 degrees Celsius, thecoloring agent on coloring element 432 begins to melt and be releasedfrom coloring element 432 and begins to diffuse through the relativelylong-term coloring agent diffusion pathway defining element 434, asdesignated by B in FIG. 4B. Thus, when the temperature exceeds 4 degreesCelsius for at least a minimum time, such as eight days, the coloringagent progresses towards the end of the pathway defined by therelatively long-term coloring agent diffusion pathway defining element434, as designated by C in FIG. 4B. When the coloring agent reachesrelatively quick coloring agent diffusion region defining element 436,it rapidly impregnates the portions of the element 436 which arereadable through the transparent areas 426 so that they appear similarlyto the bar code in the first readable state 424 and can be read togethertherewith as a single bar code as in the state designated by D in FIG.4B.

Reference is now made to FIG. 4C, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 221 ofFIG. 2C for separately indicating elapse of time and temperaturehistory. As seen in FIG. 4C, the indicator, here designated by referencenumeral 440, preferably includes a bar code defining layer 442, which ispreferably printed on a transparent substrate. The printing on thetransparent substrate preferably defines a bar code in a first readablestate 444 and alongside it, at a first end thereof, a first plurality oftransparent areas 446, which, if colored and read together with the barcode in the first readable state 444, provide a bar code in a secondreadable state 448.

The printing on the transparent substrate also preferably definesalongside the bar code in a first readable state 444, at a second endthereof, a second plurality of transparent areas 450, which, if coloredand read together with the bar code in the first readable state 444,provide a bar code in a third readable state 452. It is appreciated thatif both the first and second pluralities of transparent areas arecolored and read together with the bar code in the first readable state,there is provided a bar code in a fourth readable state 454.

The printing on the transparent substrate also preferably definesalongside the second plurality of transparent areas 450, a thirdplurality of transparent areas 456, which, if colored and read togetherwith the bar code in the first readable state 444 and the colored secondplurality of transparent areas 450, provide a bar code in a fifthreadable state (not shown). It is appreciated that if the first, secondand third pluralities of transparent areas 446, 450 and 456 are allcolored and read together with the bar code in the first readable state444, there is provided a bar code in a sixth readable state 458.

It is appreciated that the remainder of the bar code defining layer 442,other than the bar code in a first readable state 444 and thetransparent areas 446, 450 and 456, is preferably printed in a whitecolor or a color defining high contrast with respect to the bar code inthe first readable state 444.

Disposed behind transparent areas 446 of bar code defining layer 442,there is preferably provided a temperature responsive coloring element460, such as a piece of paper impregnated with a coloring agent, such asNigrosine, Alcohol soluble, a black color dye [CAS: 11099-03-9],commercially available from Acros Organics of Geel, Belgium, dissolvedin 2′-Hydroxyacetophenone 99.9% solvent [CAS: 118-93-4], commerciallyavailable from Acros Organics of Geel, Belgium. Disposed intermediatetemperature responsive color element 460 and bar code defining layer 442at transparent areas 446 is an opaque layer 462 of a color which defineshigh contrast with respect to the bar code in a first readable state444.

Disposed behind transparent areas 450 of bar code defining layer 442 isa first elapsed time responsive coloring assembly 470, including atemperature responsive release coloring element 472, a relativelylong-term coloring agent diffusion pathway defining element 474 and arelatively quick coloring agent diffusion region defining element 476.The temperature responsive release coloring element 472 preferablycomprises a substrate, such as paper or a non-woven fabric impregnatedwith a coloring agent, such as Nigrosine, Alcohol soluble, a black colordye [CAS: 11099-03-9], commercially available from Acros Organics ofGeel, Belgium, dissolved in 2′-Hydroxyacetophenone 99.9% solvent [CAS:118-93-4], commercially available from Acros Organics of Geel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 474 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 472 and an oppositeend of which extends to element 476. Relatively quick coloring agentdiffusion region defining element 476 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 474, thus ensuring that a timewhen the bar code is between its first and second readable states isminimized. It is appreciated that alternatively element 476 may beobviated and element 474 extends under all of transparent areas 450.

Disposed behind transparent areas 456 of bar code defining layer 442 andbehind first elapsed time responsive coloring assembly 470 is a secondelapsed time responsive coloring assembly 480, including a temperatureresponsive release coloring element 482, a relatively long-term coloringagent diffusion pathway defining element 484 and a relatively quickcoloring agent diffusion region defining element 486. The temperatureresponsive release coloring element 482 preferably comprises asubstrate, such as paper or a non-woven fabric impregnated with acoloring agent, such as Nigrosine, Alcohol soluble, a black color dye[CAS: 11099-03-9], commercially available from Acros Organics of Geel,Belgium, dissolved in 2′-Hydroxyacetophenone 99.9% solvent [CAS:118-93-4], commercially available from Acros Organics of Geel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 484 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 482 and an oppositeend of which extends to element 486. Relatively quick coloring agentdiffusion region defining element 486 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 484, thus ensuring that a timewhen the bar code is between its first and second readable states isminimized. It is appreciated that alternatively element 486 may beobviated and element 484 extends under all of transparent areas 456. Itis also appreciated that the first and second elapsed time responsivecoloring assemblies 470 and 480 are constructed, positioned andoperative so that they do not interfere with each other.

When the indicator 440 is maintained at 4 degrees Celsius, andsubstantially no time has elapsed since actuation of the indicator, theindicator is in the state shown designated by A in FIG. 4C.

When the temperature at the indicator rises above 4 degrees Celsius, thecoloring agent on coloring element 460 begins to melt and be releasedfrom coloring element 460 and begins to diffuse through the opaque layer462. When the temperature exceeds 4 degrees Celsius for at least aminimum time, such as five minutes, the coloring agent rapidly diffusesthrough opaque layer 462, such that the portions of the opaque layer 462which are readable through the transparent areas 446 appear similarly tothe bar code in the first readable state 444 and can be read togethertherewith as a single bar code as in the state designated by B in FIG.4C.

The coloring agent on coloring element 472 begins to melt generallyimmediately and be released from coloring element 472 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 474. When the elapsed time is greater than a firstpredetermined time, such as one week, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 474 and reachesrelatively quick coloring agent diffusion region defining element 476,where it rapidly impregnates the portions of the element 476 which arereadable through the transparent areas 450 so that they appear similarlyto the bar code in the first readable state 444 and can be read togethertherewith as a single bar code as in the state designated by C in FIG.4C.

When the elapsed time is greater than the first predetermined time andthe temperature has exceeded 4 degrees Celsius, such as 15 degreesCelsius, both transparent areas 446 and 450 are colored and can be readtogether with the bar code in the first readable state 444 as a singlebar code as in the state designated by D in FIG. 4C.

The coloring agent on coloring element 482 begins to melt generallyimmediately and be released from coloring element 482 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 484. When the elapsed time is greater than a secondpredetermined time, such as two weeks, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 484 and reachesrelatively quick coloring agent diffusion region defining element 486,where it rapidly impregnates the portions of the element 486 which arereadable through the transparent areas 456 so that they appear similarlyto the bar code in the first readable state 444 and can be read togethertherewith and with the colored transparent areas 450 as a single barcode. 101171 When the elapsed time is greater than the secondpredetermined time and the temperature has exceeded 4 degrees Celsius,such as 15 degrees Celsius, transparent areas 446, 450 and 456 are allcolored and can be read together with the bar code in the first readablestate 444 as a single bar code as in the state designated by E in FIG.4C.

Reference is now made to FIG. 4D, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 232 ofFIG. 2D for indicating two different levels of pH. As seen in FIG. 4D,the indicator, here designated by reference numeral 490, preferablyincludes a bar code defining layer 492, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 494 andalongside it, at an end thereof, a first plurality of transparent areas496, which, if colored and read together with the bar code in the firstreadable state 494, provide a bar code in a second readable state 498.

The printing on the transparent substrate also preferably definesalongside the first plurality of transparent areas 496, a secondplurality of transparent areas 500, which, if colored and read togetherwith the bar code in the first readable state 494 and the colored firstplurality of transparent areas 496, provide a bar code in a thirdreadable state 502.

It is appreciated that the remainder of the bar code defining layer 492,other than the bar code in a first readable state 494 and thetransparent areas 496 and 500, is preferably printed in a white color ora color defining high contrast with respect to the bar code in the firstreadable state 494.

Disposed behind transparent areas 496 of bar code defining layer 492,there is preferably provided a pH responsive coloring element 504, suchas a piece of litmus type paper which normally appears in a white coloror a color defining high contrast with respect to the bar code in thefirst readable state 494. Element 504 preferably is responsive toexposure to a fluid of pH less than 6 to change its color to a colordefining high contrast with the remainder of the bar code defining layer492, preferably a color similar to that of the bar code in the firstreadable state 494.

Disposed behind transparent areas 500 of bar code defining layer 442,there is preferably provided a pH responsive coloring element 506, suchas a piece of litmus type paper which normally appears in a white coloror a color defining high contrast with respect to the bar code in thefirst readable state 494. Element 506 preferably is responsive toexposure to a fluid of pH less than 5 to change its color to a colordefining high contrast with the remainder of the bar code defining layer492, preferably a color similar to that of the bar code in the firstreadable state 494.

A fluid conduit, such as a hollow pin 508, supplies a sample of thecontents of the container 230 of FIG. 2D, such as milk, to coloringelements 504 and 506.

When the contents of container 230 are maintained at a pH at or above 6,the indicator 490 is in the state designated by A in FIG. 4D.

When the contents of container 230 reach a pH below 6, the pH responsivecoloring element 504 changes color, such that the portions of thecoloring element 504 which are readable through the transparent areas496 appear similarly to the bar code in the first readable state 494 andcan be read together therewith as a single bar code in second readablestate 498, as designated by B in FIG. 4D.

When the contents of container 230 reach a pH below 5, the pH responsivecoloring element 506 changes color, such that the portions of thecoloring element 506 which are readable through the transparent areas500 appear similarly to the bar code in the first readable state 494 andcan be read together therewith and with the colored portions of the barcode which are readable through the transparent areas 496 as a singlebar code in third readable state 502, as designated by C in FIG. 4D.

It is appreciated that as an alternative to the structure describedhereinabove with reference to FIG. 4D, the entire indicator may belocated within container 230 such that coloring elements 504 and 506 arein communication with the fluid therein and pin 508 may be obviated. Insuch a case, the indicator 490 may be viewed through a transparentwindow formed in a wall of the container 230.

Reference is now made to FIG. 4E, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 242 ofFIG. 2E for indicating humidity history. As seen in FIG. 4E, theindicator, here designated by reference numeral 520, preferably includesa bar code defining layer 522, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 524 andalongside it, at an end thereof, a plurality of transparent areas 526,which, if colored and read together with the bar code in the firstreadable state 524, provide a bar code in a second readable state 528.

It is appreciated that the remainder of the bar code defining layer 522,other than the bar code in a first readable state 524 and thetransparent areas 526, is preferably printed in a white color or a colordefining high contrast with respect to the bar code in the firstreadable state 524.

Disposed behind transparent areas 526 of bar code defining layer 522,there is preferably provided a humidity responsive coloring element 530,such as a substrate coated with silica gel which normally appears in afirst color or a color defining high contrast with respect to the barcode in the first readable state 524. Element 530 preferably isresponsive to exposure to relative humidity of more than 50% to changeits color to a color defining high contrast with the remainder of thebar code defining layer 522, preferably a color similar to that of thebar code in the first readable state 524.

A fluid conduit, such as a hollow pin 532, supplies a sample of thefluid inside the container 240 of FIG. 2E, such as air, to coloringelement 530.

When the contents of container 240 are maintained at a relative humidityof less than 50%, such as 15%, the indicator 520 is in the statedesignated by A in FIG. 4E.

When the contents of container 240 reach a relative humidity in excessof 50%, such as 60%, the coloring element 530 changes color, such thatthe portions of the coloring element 530 which are readable through thetransparent areas 526 appear similarly to the bar code in the firstreadable state 524 and can be read together therewith as a single barcode in second readable state 528, as designated by B in FIG. 4E.

It is appreciated that as an alternative to the structure describedhereinabove with reference to FIG. 4E, the entire indicator may belocated within the container such that coloring element 530 is incommunication with the fluid therein and pin 532 may be obviated. Insuch a case, the indicator 520 may be viewed through a transparentwindow formed in a wall of the container 240 or the indicator 520 maymeasure the relative humidity outside the container 240 rather thaninteriorly thereof.

Reference is now made to FIG. 4F, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 252 ofFIG. 2F for indicating impact history. As seen in FIG. 4F, theindicator, here designated by reference numeral 540, preferably includesa bar code defining layer 542, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 544 andalongside it, at an end thereof, a plurality of transparent areas 546,which, if colored and read together with the bar code in the firstreadable state 544, provide a bar code in a second readable state 548.

It is appreciated that the remainder of the bar code defining layer 542,other than the bar code in a first readable state 544 and thetransparent areas 546, is preferably printed in a white color or a colordefining high contrast with respect to the bar code in the firstreadable state 544.

Disposed behind transparent areas 546 of bar code defining layer 542,there is preferably provided an impact responsive coloring assemblyelement 550, such as a substrate 552 including a surface portion 554facing the bar code defining layer 542, which has a color defining highcontrast with the remainder of the bar code defining layer 542,preferably a color similar to that of the bar code in the first readablestate 544. Mounted, in a impact sensitive manner, over surface portion554 and intermediate surface portion 554 and transparent areas 546 is acover assembly 556, having a surface portion 560, facing the bar codedefining layer 542, which has a color defining high contrast withrespect to the bar code in the first readable state 544. Uponapplication of at least a predetermined impact force, such as 10G, oneor more pins 562, which, when intact, prevent displacement of coverassembly 556 from blocking surface portion 554, are broken or removed,allowing cover assembly 556 to be displaced and thus allow surfaceportion 554 to be seen through transparent areas 546.

When the package 250 of FIG. 2F has not experienced an impact forcegreater than the predetermined impact force, the indicator 540 displaysa bar code in first readable state 544 as designated by A in FIG. 4F.

When an impact force of at least the predetermined impact force isapplied to the package 250, breakage or removal of one or more pins 562results, as indicated at B in FIG. 4F.

Thereafter, as indicated at C in FIG. 4F, colored surface portion 554 isreadable through transparent areas 546, thus providing a bar code insecond readable state 548.

Reference is now made to FIG. 4G, which is a simplified illustration ofthe construction and operation of one embodiment of the indicator 262 ofFIG. 2G for indicating orientation history. As seen in FIG. 4G, theindicator, here designated by reference numeral 570, preferably includesa bar code defining layer 572, which is preferably printed on atransparent substrate. The printing on the transparent substratepreferably defines a bar code in a first readable state 574 andalongside it, at an end thereof, a plurality of transparent areas 576,which, if colored and read together with the bar code in the firstreadable state 574, provide a bar code in a second readable state 578.

It is appreciated that the remainder of the bar code defining layer 572,other than the bar code in a first readable state 574 and thetransparent areas 576, is preferably printed in a white color or a colordefining high contrast with respect to the bar code in the firstreadable state 574.

Disposed behind transparent areas 576 of bar code defining layer 572,there is preferably provided an orientation responsive coloring assemblyelement 580, such as a substrate 582 including a surface portion 584facing the bar code defining layer 572, which has a color defining highcontrast with the remainder of the bar code defining layer 572,preferably a color similar to that of the bar code in the first readablestate 574. Mounted, in an orientation sensitive manner, over surfaceportion 584 and intermediate surface portion 584 and transparent areas576 is a cover assembly 588, having a surface portion 590, facing thebar code defining layer 572, which has a color defining high contrastwith respect to the bar code in the first readable state 574. The coverassembly 588 is normally kept in place over surface portion 584 by aplurality of pins 592 arranged so as to allow displacement of the coverassembly 588 only when the orientation of the indicator is changed by atleast 170 degrees. Upon a change of orientation of at least 170 degrees,the cover assembly 588 is displaced and thus allows surface portion 584to be seen through transparent areas 576.

When the package 260 of FIG. 2G has not experienced a change inorientation typically of at least 170 degrees, the indicator 570displays a bar code in first readable state 574 as designated by A inFIG. 4G.

When a change of orientation of at least 170 degrees is applied to thepackage 260, displacement of cover assembly 588 results, as indicated atB in FIG. 4G.

Thereafter, as indicated at C in FIG. 4G, colored surface portion 584 isreadable through transparent areas 576, thus providing a bar code insecond readable state 578.

Reference is now made to FIG. 5A, which is a simplified illustration ofthe construction and operation of one example of an indicator suitablefor use as the indicator 302 of FIG. 3A, for separately indicatingelapsed time and temperature in accordance with a preferred embodimentof the present invention. The indicator, here designated by referencenumeral 600, is a two-dimensional indicator which includes a pluralityof fixed machine-readable cells 602, mainly arranged along the peripheryof the indicator to provide an indication of orientation andregistration, and a plurality of variable machine-readable cells 604,which separately indicate elapsed time and temperature.

As seen in FIG. 5A, indicator 600 preferably includes a machine-readablecode defining layer 606, which is preferably printed on a transparentsubstrate. The printing on the transparent substrate preferably definesa two-dimensional machine-readable code in a first readable state 607,which includes the fixed machine-readable cells 602, and a plurality oftransparent areas which include one or more variable machine-readablecells 604. In the illustrated embodiment, the transparent areas arethree in number and designated by reference numerals 610, 612 and 614.

If transparent area 610 is colored and read together with thetwo-dimensional machine-readable code in a first readable state 607 itprovides a machine-readable code in a second readable state 616.

If transparent area 612 is colored and read together with thetwo-dimensional machine-readable code in a first readable state 607 itprovides a machine-readable code in a third readable state 618.

If transparent areas 610, 612 and 614 are all colored and read togetherwith the two-dimensional machine-readable code in a first readable state607 they provide a machine readable code in a fourth readable state 620.

If transparent areas 612 and 614 are both colored and read together withthe two-dimensional machine-readable code in a first readable state 607they provide a machine readable code in a fifth readable state 622.

It is appreciated that the remainder of the machine-readable codedefining layer 602, other than the machine-readable code in a firstreadable state 607 and the transparent areas 610, 612 and 614, ispreferably printed in a white color or a color defining high contrastwith respect to the machine-readable code in the first readable state607.

Disposed behind transparent area 610 of machine-readable code defininglayer 606 there is preferably provided a temperature responsive coloringelement 624, such as a piece of paper impregnated with a coloring agent,such as Nigrosine, Alcohol soluble, a black color dye [CAS: 11099-03-9],commercially available from Acros Organics of Geel, Belgium, dissolvedin 2′-Hydroxyacetophenone 99.9% solvent [CAS: 118-93-4], commerciallyavailable from Acros Organics of Geel, Belgium. Disposed intermediatetemperature responsive color element 624 and machine-readable codedefining layer 606 at transparent areas 610 is an opaque layer 626 of acolor which defines high contrast with respect to the machine-readablecode in a first readable state 607.

Disposed behind transparent area 612 of machine-readable code defininglayer 606 is a first elapsed time responsive coloring assembly 634,including a coloring element 636, a relatively long-term coloring agentdiffusion pathway defining element 638 and a relatively quick coloringagent diffusion region defining element 640. The coloring element 636preferably comprises a substrate, such as paper or a non-woven fabricimpregnated with a coloring agent, such as Nigrosine, Alcohol soluble, ablack color dye [CAS: 11099-03-9], commercially available from AcrosOrganics of Geel, Belgium, dissolved in 2′-Hydroxyacetophenone 99.9%solvent [CAS: 118-93-4], commercially available from Acros Organics ofGeel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 638 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 636 and an oppositeend of which extends to element 640. Relatively quick coloring agentdiffusion region defining element 640 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 638, thus ensuring that a timewhen the machine-readable code is between its first and second readablestates is minimized. It is appreciated that alternatively element 640may be obviated and element 638 extends under all of transparent area612.

Disposed behind transparent area 614 of machine-readable code defininglayer 606 is a second elapsed time responsive coloring assembly 644,including a coloring element 646, a relatively long-term coloring agentdiffusion pathway defining element 648 and a relatively quick coloringagent diffusion region defining element 650. The coloring element 646preferably comprises a substrate, such as paper or a non-woven fabricimpregnated with a coloring agent, such as Nigrosine, Alcohol soluble, ablack color dye [CAS: 11099-03-9], commercially available from AcrosOrganics of Geel, Belgium, dissolved in 2′-Hydroxyacetophenone 99.9%solvent [CAS: 118-93-4], commercially available from Acros Organics ofGeel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 648 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 646 and an oppositeend of which extends to element 650. Relatively quick coloring agentdiffusion region defining element 650 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 648, thus ensuring that a timewhen the machine-readable code is between readable states is minimized.It is appreciated that alternatively element 650 may be obviated andelement 648 extends under all of transparent area 614.

When the indicator 600 is maintained at 4 degrees Celsius, andsubstantially no time has elapsed since actuation of the indicator, theindicator is in the state designated by A in FIG. 5A.

When the temperature at the indicator 600 rises above 4 degrees Celsius,the coloring agent on coloring element 624 begins to melt and bereleased from coloring element 624 and begins to diffuse through theopaque layer 626. When the temperature exceeds 4 degrees Celsius for atleast a minimum time, such as five minutes, the coloring agent rapidlydiffuses through opaque layer 626, such that the portions of the opaquelayer 626 which are readable through the transparent area 610 appearssimilarly to the machine-readable code in the first readable state 607and can be read together therewith as a single bar code in the secondreadable state 616 as designated by B in FIG. 5A.

The coloring agent on coloring element 636 begins to melt generallyimmediately and be released from coloring element 636 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 638. When the elapsed time is greater than a firstpredetermined time, such as one week, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 638 and reachesrelatively quick coloring agent diffusion region defining element 640,where it rapidly impregnates the portion of the element 640 which isreadable through the transparent area 612 so that it appears similarlyto the machine-readable code in the first readable state 607 and can beread together therewith as a single bar code in the third readable state618 as designated by C in FIG. 5A.

The coloring agent on coloring element 646 begins to melt generallyimmediately and be released from coloring element 646 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 648. When the elapsed time is greater than a secondpredetermined time, such as two weeks, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 648 and reachesrelatively quick coloring agent diffusion region defining element 650,where it rapidly impregnates the portions of the element 650 which arereadable through the transparent area 614 so that they appear similarlyto the machine-readable code in the first readable state 607 and can beread together therewith and with the colored transparent area 612 as asingle machine-readable code.

When the elapsed time is greater than the second predetermined time andthe temperature has exceeded 4 degrees Celsius, such as 15 degreesCelsius, transparent areas 610, 612 and 614 are all colored and can beread together with the machine-readable code in the first readable state607 as a single machine-readable code in the fourth readable state 620as designated by D in FIG. 5A.

When the elapsed time is greater than the second predetermined time andthe temperature has not exceeded 4 degrees Celsius, transparent areas612 and 614 are both colored and can be read together with themachine-readable code in the first readable state 607 as a singlemachine-readable code in the fifth readable state 622 as designated by Ein FIG. 5A.

Reference is now made to FIG. 5B, which is a simplified illustration ofthe construction and operation of one example of an indicator suitablefor use as the indicator 322 of FIG. 3B, for separately indicatinghumidity and temperature in accordance with a preferred embodiment ofthe present invention. The indicator, here designated by referencenumeral 660, is a two-dimensional indicator which includes a pluralityof fixed machine-readable cells 662, mainly arranged along the peripheryof the indicator to provide an indication of orientation andregistration, and a plurality of variable machine-readable cells 664,which separately indicate humidity and temperature.

As seen in FIG. 5B, indicator 660 preferably includes a machine-readablecode defining layer 666, which is preferably printed on a transparentsubstrate. The printing on the transparent substrate preferably definesa two-dimensional machine-readable code in a first readable state 667,which includes the fixed machine-readable cells 662, and a plurality oftransparent areas which include variable machine-readable cells 664. Inthe illustrated embodiment, the transparent areas are three in numberand designated by reference numerals 670, 672 and 674.

If transparent areas 670 and 672 are both colored and read together withthe two-dimensional machine-readable code in a first readable state 667they provide a machine readable code in a second readable state (notshown).

If transparent areas 670, 672 and 674 are all colored and read togetherwith the two-dimensional machine-readable code in a first readable state667 they provide a machine readable code in a third readable state 680.

It is appreciated that the remainder of the machine-readable codedefining layer 666, other than the machine-readable code in a firstreadable state 667 and the transparent areas 670, 672 and 674, ispreferably printed in a white color or a color defining high contrastwith respect to the machine-readable code in the first readable state667.

Disposed behind transparent area 670 of machine-readable code defininglayer 666 there is preferably provided a first temperature responsivecoloring element 684, such as a piece of paper impregnated with acoloring agent, such as Nigrosine, Alcohol soluble, a black color dye[CAS: 11099-03-9], commercially available from Acros Organics of Geel,Belgium, dissolved in 2′-Hydroxyacetophenone 99.9% solvent [CAS:118-93-4], commercially available from Acros Organics of Geel, Belgium.Disposed intermediate temperature responsive color element 684 andmachine-readable code defining layer 666 at transparent area 670 is anopaque layer 686 of a color which defines high contrast with respect tothe machine-readable code in a first readable state 667.

Disposed behind transparent area 672 of machine-readable code defininglayer 666 there is preferably provided a second temperature responsivecoloring element 694, such as a piece of paper impregnated with acoloring agent, such as Nigrosine, Alcohol soluble, a black color dye[CAS: 11099-03-9], commercially available from Acros Organics of Geel,Belgium, dissolved in 2′-Hydroxyacetophenone 99.9% solvent [CAS:118-93-4], commercially available from Acros Organics of Geel, Belgium.Disposed intermediate temperature responsive color element 694 andmachine-readable code defining layer 666 at transparent area 672 is anopaque layer 696 of a color which defines high contrast with respect tothe machine-readable code in a first readable state 667.

Disposed behind transparent area 674 of machine-readable code defininglayer 666 there is preferably provided a humidity responsive coloringelement 704, such as a substrate coated with silica gel which normallyappears in a first color or a color defining high contrast with respectto the machine-readable code in the first readable state 667. Element704 preferably is responsive to exposure to relative humidity of morethan 50% to change its color to a color defining high contrast with theremainder of the machine-readable code defining layer 666, preferably acolor similar to that of the machine-readable code in the first readablestate 667.

A fluid conduit, such as a hollow pin 706, supplies a sample of thefluid inside the container 320 of FIG. 3B, such as air, to coloringelement 704.

When the contents of container 320 are maintained at a relative humidityof less than 50%, such as 15%, and at a temperature of less than 30degrees Celsius, the indicator 660 is in the first readable state 667designated by A in FIG. 5B.

When the contents of container 320 reach a temperature of more than 30degrees Celsius, such as 33 degrees Celsius, the coloring agent oncoloring element 684 begins to melt and be released from coloringelement 684 and begins to diffuse through the opaque layer 686. When thetemperature exceeds 30 degrees Celsius for at least a minimum time, suchas five minutes, the coloring agent rapidly diffuses through opaquelayer 686, such that the portion of the opaque layer 686 which isreadable through the transparent area 670 appears similarly to themachine-readable code in the first readable state 667.

When the contents of container 320 reach a temperature of more than 30degrees Celsius, such as 33 degrees Celsius, the coloring agent oncoloring element 694 also begins to melt and be released from coloringelement 694 and begins to diffuse through the opaque layer 696. When thetemperature exceeds 30 degrees Celsius for at least a minimum time, suchas five minutes, the coloring agent rapidly diffuses through opaquelayer 696, such that the portion of the opaque layer 696 which isreadable through the transparent area 672 appears similarly to themachine-readable code in the first readable state 667.

When the contents of container 320 reach a relative humidity in excessof 50%, such as 60%, the coloring element 704 changes color, such thatthe portion of the coloring element 704 which is readable through thetransparent area 674 appears similarly to the machine-readable code inthe first readable state 667 and can be read together therewith and withthe colored transparent areas 670 and 672 as a single bar code in secondreadable state 676, as designated by B in FIG. 5B.

It is appreciated that as an alternative to the structure describedhereinabove with reference to FIG. 5B, the entire indicator may belocated within the container such that coloring element 704 is incommunication with the fluid therein and pin 706 may be obviated. Insuch a case, the indicator 660 may be viewed through a transparentwindow formed in a wall of the container 320 or the indicator 660 maymeasure the relative humidity outside the container 320 rather thaninteriorly thereof.

It is appreciated that in this embodiment multiple areas providetemperature information. It is appreciated that multiple areas may beused to indicate multiple temperature levels and/or to provideredundancy in indicating the same temperature level.

Reference is now made to FIG. 5C, which is a simplified illustration ofthe construction and operation of one example of an indicator suitablefor use as the indicator 352 of FIG. 3C, for separately indicatingelapsed time, humidity and temperature in accordance with a preferredembodiment of the present invention. The indicator, here designated byreference numeral 720, is a two-dimensional indicator which includes aplurality of fixed machine-readable cells 722, mainly arranged along theperiphery of the indicator to provide an indication of orientation andregistration, and a plurality of variable machine-readable cells 724which separately indicate elapsed time, humidity and temperature.

As seen in FIG. 5C, indicator 720 preferably includes a machine-readablecode defining layer 726, which is preferably printed on a transparentsubstrate. The printing on the transparent substrate preferably definesa two-dimensional machine-readable code in a first readable state 727,which includes the fixed machine-readable cells 722, and a plurality oftransparent areas which include variable machine-readable cells 724. Inthe illustrated embodiment, the transparent areas are six in number anddesignated by reference numerals 730, 732, 734, 736, 738 and 739.

If transparent areas 730, 734 and 738 are colored and read together withthe two-dimensional machine-readable code in a first readable state 727they provides a machine readable code in a second readable state 740.

If transparent areas 730, 732, 734, 736, 738 and 739 are all colored andread together with the two-dimensional machine-readable code in a firstreadable state 727 they provide a machine readable code in a thirdreadable state 742.

It is appreciated that the remainder of the machine-readable codedefining layer 726, other than the machine-readable code in a firstreadable state 727 and the transparent areas 730, 732, 734, 736, 738 and739, is preferably printed in a white color or a color defining highcontrast with respect to the machine-readable code in the first readablestate 727.

Disposed behind transparent area 730 of machine-readable code defininglayer 726 there is preferably provided a first elapsed time responsivecoloring assembly 744, including a coloring element 746, a relativelylong-term coloring agent diffusion pathway defining element 748 and arelatively quick coloring agent diffusion region defining element 750.The coloring element 746 preferably comprises a substrate, such as paperor a non-woven fabric impregnated with a coloring agent, such asNigrosine, Alcohol soluble, a black color dye [CAS: 11099-03-9],commercially available from Acros Organics of Geel, Belgium, dissolvedin 2′-Hydroxyacetophenone 99.9% solvent [CAS: 118-93-4], commerciallyavailable from Acros Organics of Geel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 748 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 746 and an oppositeend of which extends to element 750. Relatively quick coloring agentdiffusion region defining element 750 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 748, thus ensuring that a timewhen the machine-readable code is between its first and second readablestates is minimized. It is appreciated that alternatively element 750may be obviated and element 748 extends under all of transparent area730.

Disposed behind transparent area 732 of machine-readable code defininglayer 726 is a second elapsed time responsive coloring assembly 754,including a coloring element 756, a relatively long-term coloring agentdiffusion pathway defining element 758 and a relatively quick coloringagent diffusion region defining element 760. The coloring element 756preferably comprises a substrate, such as paper or a non-woven fabricimpregnated with a coloring agent, such as Nigrosine, Alcohol soluble, ablack color dye [CAS: 11099-03-9], commercially available from AcrosOrganics of Geel, Belgium, dissolved in 2′-Hydroxyacetophenone 99.9%solvent [CAS: 118-93-4], commercially available from Acros Organics ofGeel, Belgium.

The relatively long-term coloring agent diffusion pathway definingelement 758 preferably comprises a strip of paper, such as Grade 3qualitative filter paper commercially available from Whatman plc of theUK, one end of which lies adjacent coloring element 756 and an oppositeend of which extends to element 760. Relatively quick coloring agentdiffusion region defining element 760 preferably comprises a strip ofpaper, such as Grade 4 qualitative filter paper commercially availablefrom Whatman plc of the UK, which has a much higher speed of diffusionfor the coloring agent than does element 758, thus ensuring that a timewhen the machine-readable code is between readable states is minimized.It is appreciated that alternatively element 760 may be obviated andelement 758 extends under all of transparent area 732.

Disposed behind transparent area 734 of machine-readable code defininglayer 726 there is preferably provided a first humidity responsivecoloring element 764, such as a substrate coated with silica gel whichnormally appears in a first color or a color defining high contrast withrespect to the machine-readable code in the first readable state 727.Element 764 preferably is responsive to exposure to relative humidity ofmore than 10% to change its color to a color defining high contrast withthe remainder of the machine-readable code defining layer 726,preferably a color similar to that of the machine-readable code in thefirst readable state 727.

A first fluid conduit, such as a first hollow pin 766, supplies a sampleof the fluid inside the package 350 of FIG. 3C, such as air, to coloringelement 764.

Disposed behind transparent area 736 of machine-readable code defininglayer 726 there is preferably provided a second humidity responsivecoloring element 774, such as a substrate coated with silica gel whichnormally appears in a first color or a color defining high contrast withrespect to the machine-readable code in the first readable state 727.Element 774 preferably is responsive to exposure to relative humidity ofmore than 40% to change its color to a color defining high contrast withthe remainder of the machine-readable code defining layer 726,preferably a color similar to that of the machine-readable code in thefirst readable state 727.

A second fluid conduit, such as a second hollow pin 776, supplies asample of the fluid inside the package 350, such as air, to coloringelement 774. Alternatively, a single fluid conduit may communicate withmultiple color elements.

Disposed behind transparent area 738 of machine-readable code defininglayer 726 there is preferably provided a first temperature responsivecoloring element 784, such as a piece of paper impregnated with acoloring agent, such as Nigrosine, Alcohol soluble, a black color dye[CAS: 11099-03-9], commercially available from Acros Organics of Geel,Belgium, dissolved in 2′-Hydroxyacetophenone 99.9% solvent [CAS:118-93-4], commercially available from Acros Organics of Geel, Belgium.Disposed intermediate temperature responsive color element 784 andmachine-readable code defining layer 726 at transparent area 738 is anopaque layer 786 of a color which defines high contrast with respect tothe machine-readable code in a first readable state 727.

Disposed behind transparent area 739 of machine-readable code defininglayer 726 there is preferably provided a second temperature responsivecoloring element 790, such as a piece of paper impregnated with acoloring agent, such as Sudan Black B, a black color dye [CAS:4197-25-5], commercially available from Acros Organics of Geel, Belgium,dissolved in DiMethyl Sulfoxide [CAS: 67-68-5], commercially availablefrom Acros Organics of Geel, Belgium. Disposed intermediate temperatureresponsive color element 790 and machine-readable code defining layer726 at transparent area 739 is an opaque layer 792 of a color whichdefines high contrast with respect to the machine-readable code in afirst readable state 727.

When the contents of package 350 are maintained at a relative humidityof less than 10%, such as 5%, and at a temperature of less than 5degrees Celsius and when less than one week has elapsed since packaging,the indicator 720 is in the first readable state 727 as designated by Ain FIG. 5C.

When the contents of package 350 reach a temperature of more than 4degrees Celsius, such as 12 degrees Celsius, the coloring agent oncoloring element 784 begins to melt and be released from coloringelement 784 and begins to diffuse through the opaque layer 786. When thetemperature exceeds 4 degrees Celsius for at least a minimum time, suchas five minutes, the coloring agent rapidly diffuses through opaquelayer 786, such that the portion of the opaque layer 786 which isreadable through the transparent area 730 appears similarly to themachine-readable code in the first readable state 727.

When the contents of package 350 reach a relative humidity in excess of10%, such as 30%, the coloring element 764 changes color, such that theportion of the coloring element 764 which is readable through thetransparent area 734 appears similarly to the machine-readable code inthe first readable state 727.

The coloring agent on coloring element 746 begins to melt generallyimmediately and be released from coloring element 746 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 748. When the elapsed time is greater than a firstpredetermined time, such as one week, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 748 and reachesrelatively quick coloring agent diffusion region defining element 750,where it rapidly impregnates the portion of the element 750 which isreadable through the transparent area 730 so that it appears similarlyto the machine-readable code in the first readable state 727.

The colored transparent areas 730, 734 and 738 can be read together withthe machine-readable code in the first readable state 727 as a singlemachine-readable code in second readable state 740 as designated by B inFIG. 5C.

When the contents of package 350 reach a temperature of more than 12degrees Celsius, such as 20 degrees Celsius, the coloring agent oncoloring element 790 begins to melt and be released from coloringelement 790 and begins to diffuse through the opaque layer 792. When thetemperature exceeds 12 degrees Celsius for at least a minimum time, suchas five minutes, the coloring agent rapidly diffuses through opaquelayer 792, such that the portion of the opaque layer 792 which isreadable through the transparent area 730 appears similarly to themachine-readable code in the first readable state 727.

When the contents of package 350 reach a relative humidity in excess of40%, such as 60%, the coloring element 774 changes color, such that theportion of the coloring element 774 which is readable through thetransparent area 736 appears similarly to the machine-readable code inthe first readable state 727.

The coloring agent on coloring element 756 begins to melt generallyimmediately and be released from coloring element 756 and begins todiffuse through relatively long-term coloring agent diffusion pathwaydefining element 758. When the elapsed time is greater than a secondpredetermined time, such as two weeks, the coloring agent progressestowards the end of the pathway defined by the relatively long-termcoloring agent diffusion pathway defining element 758 and reachesrelatively quick coloring agent diffusion region defining element 760,where it rapidly impregnates the portion of the element 760 which isreadable through the transparent area 732 so that it appears similarlyto the machine-readable code in the first readable state 727.

The colored transparent areas 730, 732, 734, 736, 738 and 739 can beread together with the machine-readable code in the first readable state727 as a single machine-readable code in third readable state 742 asdesignated by C in FIG. 5C.

It is appreciated that while the illustrated embodiments of FIGS. 5A-5Cinclude transparent areas including multiple variable machine-readablecells, each of the transparent areas may include a single variablemachine-readable cell or multiple variable machine-readable cells.Typically, transparent areas include multiple variable machine-readablecells to enhance readability.

Reference is now made to FIG. 6, which illustrates a method andapparatus for producing indicators 802 constructed and operative inaccordance with the present invention, such as the indicators describedhereinabove with reference to FIG. 4A, preferably on a “just in time”basis. As seen in FIG. 6, three continuous substrate strips areprovided: a strip 804 of a transparent material, such as plastic, onwhich appears a bar code in a first readable state 805 and alongside ita plurality of transparent areas 806, a strip 807 of an opaque material,corresponding to opaque layer 412 in the embodiment of FIG. 4A, and astrip 808 having formed thereon at predetermined locations therealong aplurality of ink impregnated regions 809, corresponding to temperatureresponsive color elements 410 in the embodiment of FIG. 4A. Strip 808 ispreferably maintained under strict temperature conditions prior to use,so that the temperature thereat does not exceed 4 degrees Celsius.

Preferably strips 804 and 807 are joined to each other, as by anadhesive. This may be done at a roller or, alternatively, strips 804 and807 may be supplied already joined together.

A series of bar code defining layers 810, each corresponding to bar codedefining layer 402 in the embodiment of FIG. 4A, is formed on strip 804by conventional printing techniques, preferably digital printingtechniques. The printing preferably takes place “just in time” so as toensure that each indicator 802 corresponds to a correct package. Theprinting on the transparent substrate preferably defines the bar code ina first readable state 805 and alongside it the plurality of transparentareas 806. It is appreciated that the remainder of the transparentsubstrate 804, other than the bar code in a first readable state 805 andthe transparent areas 806, is preferably printed in a white color or acolor defining high contrast with respect to the bar code in the firstreadable state 805.

Strips 804, 807 and 808 are laminated together in suitable registrationas shown generally at roller 812 by any suitable technique, such as theuse of heat or adhesive. Preferably a perforator 814 forms a perforationline between adjacent indicators 802 in order to enhance the ease ofseparating individual indicators.

It is appreciated that similar manufacturing techniques may be employed,as appropriate for other indicators.

Reference is now made to FIG. 7A, which illustrates the structure andoperation of a quality management system constructed and operative inaccordance with a preferred embodiment of the present invention in thecontext of a supermarket. In the embodiment of FIG. 7A, packagedproducts 820 each bear an event indicator 822 of the general typedescribed hereinabove and illustrated in FIGS. 1-5C and including one ormore of the operational and structural features described hereinabove.

In the illustrated embodiment, indicator 822 preferably presents avariable bar code 824 which includes a product designator. Such a barcode may, but need not necessarily, include a UPC code. When this codeis read, as by a conventional bar code reader 826 used by a stockchecker or by a conventional checkout scanner 828, it provides productidentification information to a product management server 830.

As described hereinabove, the bar code 824 is preferably a variable barcode which, depending on the product, may provide bar code readableindications of one or more event parameters, such as temperature andelapsed time, and for each such parameter may indicate multiple levels.For example, where the packaged product 820 is fresh rib steak, asshown, the bar code 824 may have multiple readable states such as:

-   FIRST READABLE STATE 0011840854—FRESH RIB STEAK TEMPERATURE DID NOT    EXCEED 4 DEGREES CELSIUS TIME DURATION FROM PACKAGING DID NOT EXCEED    3 DAYS-   SECOND READABLE STATE 350011840854—FRESH RIB STEAK TEMPERATURE DID    NOT EXCEED 4 DEGREES CELSIUS TIME DURATION FROM PACKAGING DID EXCEED    3 DAYS BUT DID NOT EXCEED 6 DAYS

THIRD READABLE STATE 53350011840854—FRESH RIB STEAK TEMPERATURE DID NOTEXCEED 4 DEGREES CELSIUS TIME DURATION FROM PACKAGING DID EXCEED 6 DAYS

FOURTH READABLE STATE 001184085412—FRESH RIB STEAK TEMPERATURE DIDEXCEED 4 DEGREES CELSIUS BUT DID NOT EXCEED 15 DEGREES CELSIUS

-   FIFTH READABLE STATE 00118408541212—FRESH RIB STEAK TEMPERATURE DID    EXCEED 15 DEGREES CELSIUS-   SIXTH READABLE STATE 35001184085412—FRESH RIB STEAK TEMPERATURE DID    EXCEED 4 DEGREES CELSIUS TIME DURATION FROM PACKAGING DID EXCEED 3    DAYS

In the illustrated embodiment, the product management server 830maintains a database which preferably contains at least the followinginformation:

BAR PRODUCT PRODUCT CODE DESCRIPTION STATUS PRICE 0011840854 FRESH RIBSTEAK OK $10/LB 350011840854 FRESH RIB STEAK QUICK SALE $ 8/LB53350011840854 FRESH RIB STEAK DO NOT SELL 001184085412 FRESH RIB STEAKQUICK SALE $ 7/LB 00118408541212 FRESH RIB STEAK DO NOT SELL35001184085412 FRESH RIB STEAK DO NOT SELL

Based on the scanned bar code, the product management server 830provides both product status information and price information asappropriate to management as well as points of sale.

Reference is now made to FIG. 7B, which illustrates the structure andoperation of a quality management system constructed and operative inaccordance with another preferred embodiment of the present invention inthe context of a supermarket. In the embodiment of FIG. 7B, packagedproducts 850 each bear an event indicator 852 of the general typedescribed hereinabove and illustrated in FIGS. 1-5C and including one ormore of the operational and structural features described hereinabove.

In the illustrated embodiment, indicator 852 preferably presents avariable bar code 854 which does not include a product designator. Aseparate bar code bearing indicator 855, including, for example, a UPCcode, may appear on each packaged product 850 or alternatively, aproduct designation may be entered manually when scanning bar code 854.

When bar code 854 is read, as by a conventional bar code reader 856,used by a stock checker or by a conventional checkout scanner 858, itprovides event information but it does not provide productidentification information to a product management server 860. Productidentification information may be entered by scanning bar code bearingindicator 855 or manually.

As described hereinabove, with reference to FIGS. 1-5C, the bar code 854is preferably a variable bar code which, depending on the product, mayprovide bar code readable indications of one or more event parameters,such as temperature and elapsed time, and for each such parameter mayindicate multiple levels. In the illustrated example, the packagedproduct 850, as shown in a Product Description Table, is fresh ribsteak, and the variable bar code 854 may have multiple readable statescorresponding to multiple events, such as shown below in an EventDescription Table.

In the illustrated embodiment of FIG. 7B, the variable bar code 854includes a first readable state 0123, a second readable state 350123, athird readable state 53350123, a fourth readable state 012312, a fifthreadable state 01231212 and a sixth readable state 35012312.

As seen in the illustrated embodiment, the product management server 860maintains a database which preferably includes at least a productdescription table, such as Table 1, and an event report table, such asTable 2.

TABLE 1 PRODUCT DESCRIPTION PRODUCT BAR CODE (855) DESCRIPTION0011840854 FRESH RIB STEAK

TABLE 2 EVENT BAR CODE (854) EVENT DESCRIPTION 0123 TEMPERATURE DID NOTEXCEED 4 DEGREES CELSIUS TIME DURATION FROM PACKAGING DID NOT EXCEED 3DAYS 350123 TEMPERATURE DID NOT EXCEED 4 DEGREES CELSIUS TIME DURATIONFROM PACKAGING DID EXCEED 3 DAYS BUT DID NOT EXCEED 6 DAYS 53350123TEMPERATURE DID NOT EXCEED 4 DEGREES CELSIUS TIME DURATION FROMPACKAGING DID EXCEED 6 DAYS 012312 TEMPERATURE DID EXCEED 4 DEGREESCELSIUS BUT DID NOT EXCEED 15 DEGREES CELSIUS 01231212 TEMPERATURE DIDEXCEED 15 DEGREES CELSIUS 35012312 TEMPERATURE DID EXCEED 4 DEGREESCELSIUS TIME DURATION FROM PACKAGING DID EXCEED 3 DAYS

Upon receipt of inputs identifying a product in Table 1 and indicatingan event description in Table 2 corresponding to the same product, theproduct management server 860 is operative to provide a product statustable, such as Table 3, typically including a product description barcode (P.D.B.C.), an event bar code (E.B.C.), a product description, aproduct status and a price, as follows:

TABLE 3 PRODUCT PRODUCT P.D.B.C. E.B.C. DESCRIPTION STATUS PRICE0011840854 0123 FRESH RIB STEAK OK $10/LB 0011840854 35013 FRESH RIBSTEAK QUICK SALE $ 8/LB 0011840854 53350123 FRESH RIB STEAK DO NOT SELL0011840854 012312 FRESH RIB STEAK QUICK SALE $ 7/LB 0011840854 01231212FRESH RIB STEAK DO NOT SELL 0011840854 35012312 FRESH RIB STEAK DO NOTSELL

The product management server 860 provides both product statusinformation and price information from Table 3 to management as well asto points of sale as appropriate.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and sub-combinations of various feature ofthe invention and modifications thereof which may occur to personsskilled in the art upon reading the foregoing description and which arenot in the prior art.

1-13. (canceled)
 14. A method for producing a plurality of productquality indicators, each operative to provide a machine-readableindication of exceedence of at least one temperature threshold, themethod comprising: providing at least one substrate strip including aplurality of barcodes in a first readable state; providing an additionalsubstrate strip having formed thereon a plurality of temperatureresponsive elements; and joining said at least one substrate strip andsaid at least one additional substrate strip to form said plurality ofproduct quality indicators, each of said plurality of product qualityindicators including one of said plurality of barcodes in a firstreadable state and one of said plurality of temperature responsiveelements, each of said plurality of temperature responsive elementsbeing operative upon exceedence of said at least one threshold to colora portion of said at least one substrate strip, thereby causing each ofsaid product quality indicators to assume a second readable state.
 15. Amethod according to claim 14 and wherein said providing at least onesubstrate strip comprises: providing a transparent substrate strip;printing, in a first color, said plurality of barcodes in said firstreadable state on said transparent substrate strip; forming a pluralityof transparent areas alongside each of said plurality of barcodes insaid first readable state by printing, in a second color, areas of saidtransparent substrate strip other than said plurality of barcodes andsaid plurality of transparent areas; providing an opaque substratestrip; and joining said transparent substrate strip and said opaquesubstrate strip.
 16. A method according to claim 15 and wherein saidsecond color is a color defining high contrast with respect to saidfirst color.
 17. A method according to claim 14 and also comprisingforming a perforation line between adjacent indicators.
 18. A methodaccording to claim 14 and also comprising maintaining said additionalsubstrate strip having formed thereon a plurality of temperatureresponsive elements below a predetermined temperature threshold prior touse.